The two different camps of flat-panel display standards will, of course, gladly spruik the advantages of their own standard and the deficiencies of the other. But what type of display — plasma or LCD — is actually better? And which will give you more bang for your buck?

Plasma and LCD technology — what's the difference?

Plasma and LCD panels may look similar, but the flat screen and the thin profile are where the similarities end. Plasma screens, as the name suggests, use a matrix of tiny gas plasma cells charged by precise electrical voltages to create a picture. LCD (liquid crystal display) screens are in layman's terms sandwiches made up of liquid crystal pushed in the space between two glass plates. Images are created by varying the amount of electrical charge applied to the crystals. Each technology has its strengths and weaknesses, as you'll read below.

(Credit: Panasonic)

Is there a difference in picture quality between plasma and LCD screens?

It's not what's happening behind the screen that's important — it's how the screen performs as a television that matters the most. In that regard, both plasma and LCD TV sets produce excellent pictures, and the differences between them aren't as pronounced as they used to be. While the latest plasmas are particularly good, LCD sets are quickly catching up in terms of quality, with advances like LED backlighting.

For basic home cinema-like usage, plasma screens have a slight edge over LCDs. This is because plasma screens can still display blacks more accurately than LCDs can, which means better contrast and detail in dark scenes. The nature of LCD technology, where a backlight shines through the LCD layer, means that it's hard for it to achieve true blacks because there's always some light leakage from between pixels. As LCD/LED technologies such as polarising filters and dynamic backlights improve, the quality gap between the technologies grows narrower.

What advantages does plasma have over LCD?

Apart from better contrast due to its ability to show deeper blacks, plasma screens typically have better viewing angles than LCD. Viewing angles are how far you can sit on either side of a screen before the picture's quality is affected. You tend to see some brightness and colour shift when you're on too much of an angle with LCDs, while a plasma's picture remains fairly solid. Plasmas can also produce richer, more natural colours, due to both light leakage and to a limit on the hues that LCD can reproduce.

Plasma pundits will also tell you that some LCD screens have a tendency to blur images, particularly during fast-moving scenes in movies or in sport. While that was true for older generation LCD screens, newer models have improved significantly — so much so that the differences in performance between LCDs and plasmas in this regard is almost negligible. (While the pixel response time, measured in milliseconds (ms), can give you some indication of an LCD's performance with fast-moving scenes, it's not always reliable.)

Traditionally, the biggest advantage that plasmas have had over their LCD cousins is price, particularly in the large screen end of the market. Depending on the resolution, plasma is still able to beat most equivalently priced LCD screens. Plasmas currently sold in Australia generally run between 42 and 65 inches wide, with the cheapest 1024x768 standard-definition 42-inch selling for under AU$1000.

At present, the mainstream plasma size is 50 inches, but sizes of 60 inches and above are becoming more common. At these sizes, plasmas tend to be two thirds or less than the price of the equivalent LCD, due to the high manufacturing cost of LCD panels.

LCDs, on the other hand, generally top out around the 60-inch mark — though there have been some ludicrously expensive 70-inch Sony LCDs available.

What advantages does LCD have over plasma?

Apart from becoming increasingly price-competitive, LCD has the edge over plasma in several other key areas. LCDs tend to have a higher native resolution than plasmas of similar size, which means more pixels on the screen.

LCDs also tend to consume less power than plasma screens, with some of the newer "Eco" LCD panels able to use half of the power than equivalent plasmas, with the trade-off being lower brightness.

In terms of bulk, LCDs are also generally lighter than similar-sized plasmas, making it easier to move around or wall-mount. This is because LCDs use plastic in their screen make-up, whereas plasmas tend to use glass.

LCD pundits point to the belief that LCDs have a longer lifespan than plasma screens. While this may have been true of earlier plasma models — which dropped to half-brightness at 20,000 hours — many modern plasmas have the same 60,000-hour lifespan as LCDs. This means that both types of TVs will last for almost seven years if left on 24 hours a day.

Recently, LCD arguably caught up to the quality of plasma with the introduction of LED backlighting. Instead of lighting the screen with fluorescent tubes, as is traditional, it uses banks of LED lights. There are two types of LED lighting: direct and edge. Direct backlighting means that the lights are mounted behind the LCD panel, while edge-lighting uses a series of LEDs along the edge of the screen. Most thin LCDs on the market use this edge-lighting, though direct lighting is arguably better for picture quality. Lastly, LED is not to be confused with OLED.

You might have also heard that plasmas suffer from screen burn-in, an affliction not commonly associated with LCDs. Screen burn-in occurs when an image is left too long on a screen, resulting in a ghost of that image "burned in". Newer plasmas are less susceptible to this, thanks to improved technology and features such as screensavers, but burn-in can still be a problem. However, after a few days most burnt-in images will fade — they are no longer permanent.

(Credit: LG)

Which is better value for me right now: plasma or LCD?

If you're in the market for a big-screen television — and we're talking 50 inches and above — then we'd suggest plasma as a safe bet. Plasmas give you more bang for your buck at the big end of town, and while LCDs can give you better resolution, plasma still has the edge in terms of picture quality.

At the smaller end of things (17- to 42-inch TVs), LCD is the only way to go if you want something slim and tasteful. And the best thing is that LCDs are getting cheaper all the time.

There has also been a lot of debate surrounding use in bright environments versus dark, cinema-like conditions. The traditional wisdom is that LCD performs better during the day due to its backlighting system, and that plasma works best in a dark environment, as it uses a glass front. Nonetheless, products like the non-reflective glass plasmas and LED-backlit LCD panels with their better blacks completely turn this logic on its head.

While these exceptions do exist, plasmas do generally perform better in the dark, and models with an anti-reflective coating — such as the new Panasonic plasmas — are the best all-rounders.

What features should I look for?

In the past couple of years, several new features have cropped up, but the most pertinent to this discussion is 3D. While it's possible to manufacture a 3D screen with both LCD technology and plasma, based on our extensive testing, a plasma screen is the best at producing 3D images and reducing the artefact known as crosstalk, or ghosted imaging. Be aware that there is still very little content available in 3D, and that the technology is still evolving. Buy a set for its 2D abilities first, and then consider 3D.

While most screens are now full high-definition (1080p), resolution is a consideration when you're looking at budget screens. Budget LCDs and plasmas feature either 1366x768 or 1024x768 (720p) resolutions. If you're buying a screen that's 42 inches or larger, though, there's now no reason to get anything less than 1080p.

It isn't all about the resolution, however; it's not the pixels, it's what you do with them. Most modern TVs, and even budget ones, will accept a 1080p input, and it depends on the quality of the scaler on-board as to how good a picture you'll get. The big names — Panasonic, Sony, Samsung and LG — usually have very good image processors that can resize the source content — whether it's DVD, Blu-ray or Freeview— to the resolution of your screen without a problem.